This report presents the results of an experimental study on 3 different hulls of crew boats intended for service to offshore wind turbines. Their hydrodynamic behaviour has been tested in various sea states representing general wave conditions that could be expected at offshore wind farms. Two main setups were used during the tests, corresponding to the hulls being connected to an offshore windmill and being free floating. The following aspects were the main subjects of investigation:
• The Response Amplitude Operators of the hulls in two different configurations and with waves coming from 3 different directions.
• The connection forces between the hulls and the wind turbine pile.
• The natural frequency of oscillation.
For the study, realistic scale models of the hulls of the crew boats were supplied by the client, Hauschildt Marine. The laboratory tests were performed by Arthur Pecher under the supervision of Jens Peter Kofoed in the deep wave basin in the Hydraulics and Coastal Engineering laboratory at Aalborg University during spring 2012.